Hardeners, epoxy resin compositions, sealants, adhesives, optical communication components, camera modules, semiconductor packaging, and electronic devices.

Abstract

This invention provides a hardener that satisfies the following conditions (i) to (iii). Condition (i) When a 1.0% by mass dimethylformamide (DMF) solution is prepared, the transmittance at a wavelength of 365 nm obtained by ultraviolet-visible spectrophotometry is 50.0% or higher. Condition (ii) When the particle size (D50: μm) representing 50% of the cumulative volume of the volumetric particle size distribution is defined as (a), and the particle size (D99: μm) representing 99% of the cumulative volume of the volumetric particle size distribution is defined as (b), (a) and (b) satisfy the following formulas (1), (2), and (3). (a) ≤ 7.0・・・(1) (b) ≤ 25.0・・・(2) (b) / (a) ≤ 4.5・・・(3)